1. Field of the Invention
The present relates to locking means applicable to casement-bolts, casement-locks, multi-bolt locks or the like for doors, casement windows or the like.
This invention is applicable to the field of house hardware.
2. The Prior Art
Many types of locking devices of the multi-bolt types are already known which permit of locking the leaf of a door, casement window or the like with respect to its dormant frame, at several levels.
Among these locking fittings one particular type usually referred to as a casement bolt consists of one or a plurality of rods actuated by means of a central mechanism secured to the leaf and actuated by the user by means of a handle. These rods are provided with locking leans such as rollers, adapted to engage keepers formed at the corresponding levels on the fixed frame.
This combination, at several levels of the door, window or the like, of rollers with keepers having a specific configuration causes the movable leaf to be pressed with a certain force against the frame while simultaneously pressing against each other the gaskets disposed at the periphery of the fixed and movable elements. Thus, a reliable air-tightness is obtained between the door, window or the like and its frame.
However, the degree of safety afforded by these known casement bolts is relatively moderate. In fact, when a locking force is exerted directly on the locking members, for instance on said rollers, as would be the case if a burglar attempted to break in from outside, the door, window or the like would be unlocked quite easily with respect to its frame.
To avoid this inconvenience, combination casement lockbolts have been developed in which the notion of lock and therefore of safety is combined with the casement lock structures mentioned hereinabove. More particularly, these casement locks comprise a mechanism incorporating a lock bolt proper actuated by a key member of which the function is to lock the control rods in their locking position. It is also known to provide these casement locks with a half-turn bolt permitting for example of closing a door without necessarily locking this door. Similarly, the locking bolt may also, in addition to the above-defined function, constitute a central locking point of the door, window or the like, by acting also as a dead lock.
Though casement locks permit of easily avoiding the shortcomings of the simple casement bolt, it is admitted that their degree of safety is still insufficient.
In fact, it should be emphasized that casement locks as a rule are fitted in the lock or front stile of the door or window, the actuating rods being slidably mounted in a groove behind a face plate secured to the door edge. This arrangement is objectionable in that it impairs appreciably and locally the strength of the door or casement window which, under these conditions, would oppose but a weak resistance in case a shock corresponding for example to the impact of a club were applied thereto.
The prior art solution brought to this problem of mechanical strength consisted in fitting the casement-locks in section members secured to the inner side of the leaf. The same solution was also applied to the keepers usually fitted in the edge of the dormant frame, thus increasing the fragility of the door, window or the like. Consequently, these keepers have been embedded in strips or section members secured to the front stile of the dormant frame, at the level of the locking members of the casement-lock. In order to further improve the mechanical strength of the assembly and, eventually, the degree of safety of the locking means of a door, window or the like, the various mechanical component elements, notably the actuating rods having a bar-like configuration, have been reinforced. Moreover, dormant keepers movable at right angles to said front stile have been substituted for the rollers moving parallel to the front stile. This modification led to the multi-bolt lock. Indisputably, these dormant keepers, due to their greater strength in comparison with the rollers, increase considerably the safety of said multi-bolt locks. However, this improved safety was obtained at the expenses of the air-tightness of the door, window or the like. In fact, as a consequence of the play existing between the leaf and the frame, the keepers had to be fitted quite loosely in relation to the dead bolts to permit the engagement of said keepers. Consequently, with this arrangement it is definitely precluded to cause the leaf to exert a pressure against its frame when locking the door, window or the like.